Device for fixing at least a part of the human cervical and/or thoracic vertebral column

Abstract

A device for fixing at least a part of the human cervical and/or thoracic vertebral column comprises at least one assembly of a plurality of fixation elements (1, 1a and 1b, 1c, respectively) arranged above each other and at least one rod or wire (2, 2a) interconnecting these fixation elements. Each fixation element comprises a substantially block-shaped body (4) and a hook projecting from the lower edge area (5) of the block-shaped body (4). A first articular process contact surface (7) is constituted by an upright side of the block-shaped body (4) that faces the hook. A second articular process contact surface (8) is constituted by the substantially upwardly directed surface of the hook (6). The first (7) and the second articular process contact surfaces (8) include an acute angle (α) and a securing means (9), in a securing position, extends into the space included by the first (7) and the second (8) vertebra contact surfaces.

I claim: 
     
       1. A device for fixing at least a part of the human vertebral column, said device comprising two assemblies, each assembly comprising a plurality of fixation elements arranged above each other and at least one rod or wire interconnecting these fixation elements, each fixation element comprising a substantially block-shaped body and a hook extending from a lower edge area of the block-shaped body, a first vertebra contact surface comprising an upright side of the block-shaped body that faces the hook and a second vertebra contact surface comprising a substantially upwardly directed surface of the hook, a securing means, which, when in a securing position, extends at least partly into the space between the first and the second vertebra contact surfaces, said vertebra contact surfaces comprising substantially flat articular process contact surfaces, the first and the second articular process contact surfaces being interconnected through a small radius and forming a V-shaped space therebetween, said two assemblies being arranged substantially parallel, the respective fixation elements of said assemblies being arranged at the same level, the assemblies being connected by means of at least one transverse rod or wire, wherein at least two fixation elements of the respective assemblies, arranged at the same level, comprise transverse connector means interconnecting said two assemblies through cooperation with the transverse rod or wire. 
     
     
       2. A device as claimed in claim 1, wherein an angle of the V-shaped space is in a range of 40°-50°. 
     
     
       3. A device as claimed in claim 1, wherein the securing means comprises a securing pin mounted in the block-shaped body such that said securing pin is movable in a direction of its longitudinal axis and extends substantially perpendicularly to the first articular process contact surface, an end of the securing pin remote from the block-shaped body (4) being located close to a free end of the hook in the securing position. 
     
     
       4. A device as claimed in claim 1, wherein the fixation elements comprise means for detachably connecting the rod or wire interconnecting the fixation elements, said means comprising at least a bore extending throughout a height of the substantially block-shaped body for receiving the rod or wire, wherein a position of the bore with respect to the securing means extending into the V-shaped space is such that a rod or wire arranged in the bore fixes the securing means in its securing position. 
     
     
       5. A device as claimed in claim 4, wherein the bore is part of a substantially L-shaped slot extending through the block-shaped body and throughout a height of the block-shaped body, a first leg of said slot terminating in a side surface of the block-shaped body that bounds the first articular process contact surface and comprising a receiving slot for the rod or wire, a second leg of said slot extending toward the hook and terminating in the bore, the rod or wire being fixable in the bore by means of a retaining screw fitted in a rear wall of the block-shaped body in line with the second leg and extending into the L-shaped slot. 
     
     
       6. A device as claimed in claim 1, wherein the transverse connector means comprise a substantially L-shaped slot extending through the block-shaped body throughout a width of the block-shaped body, a first leg of said slot terminating in a bottom surface of the block-shaped body and comprising a receiving slot for the transverse rod or wire a second leg of said slot extending toward the hook, the transverse rod being fixable in the second leg of the L-shaped slot by means of a retaining screw fitted in a rear wall of the block-shaped body in line with the second leg and extending into the L-shaped slot. 
     
     
       7. A device as claimed in claim 6, wherein the securing means comprises a securing pin mounted in the block-shaped body such that said securing pin is movable in a direction of its longitudinal axis and extends substantially perpendicularly to the first articular process contact surface, an end of the securing pin remote from the block-shaped body being located close to a free end of the hook in the securing position. 
     
     
       8. A device as claimed in claim 6, wherein the fixation elements comprise means for detachably connecting the rod or wire interconnecting the fixation elements, said means comprising at least a bore extending throughout a height of the substantially block-shaped body for receiving the rod or wire, wherein a position of the bore with respect to the securing means extending into the V-shaped space is such that a rod or wire arranged in the bore fixes the securing means in its securing position. 
     
     
       9. A device as claimed in claim 8, wherein the bore is part of a substantially L-shaped slot extending through the block-shaped body and throughout a height of the block-shaped body, a first leg of said slot terminating in a side surface of the block-shaped body that bounds the first articular process contact surface and comprising a receiving slot for the rod or wire, a second leg of said slot extending toward the hook and terminating in the bore, the rod or wire being fixable in the bore by means of a retaining screw fitted in a rear wall of the block-shaped body in line with the second leg and extending into the L-shaped slot.